As taught in U.S. Pat. No. 4,974,648 which issued to Propst on Dec. 4, 1990, lopping implements have been suspended from a suitable lifting tackle which is mounted on a separate chassis. The lopping implements are lowered onto a felled tree. As the implement is lowered, the grippers are open and they subsequently engage the tree trunk from below and hold and guide it as it is processed. When the implement has been applied to the tree trunk and has subsequently been raised, the feeding means move the tree past knife edges facing opposite to the feeding direction and which may be secured to separate toolholders or directly to gripper arms. As a result, the tree is lopped throughout the periphery of the tree trunk as the tree is pulled through the implement. A cross-cutting device may optionally be provided for cross-cutting the tree trunk when the tree has been lopped so that felled trees can efficiently be treated.
As discussed in Canadian Patent No. 2,162,183, which issued to Kingston on Aug. 11, 1998, modern tree harvesting operations generally comprise equipment such as a land vehicle with large diameter wheels or a pair of crawler tracks. The vehicle is generally equipped with a multi-function tree processing apparatus mounted at the end of an articulated boom. The tree processing apparatus may fell a tree, delimb it and sever or buck the tree trunk into sawmill length logs in a single sequence of operation.
In the prior art, applicant is aware of multi-function tree processing apparatus such as disclosed in U.S. Pat. Nos. 4,766,939, issued on Aug. 30, 1988 to Forslund, and U.S. Pat. No. 5,219,010 issued on Jun. 14, 1993 to Eriksson. Examples of conventional delimbing machines are described in U.S. Pat. No. 4,276,918 which issued on Jul. 7, 1981 to Sigouin, and in U.S. Pat. No. 4,382,457 which issued on May 10, 1983 to Hahn. Sigouin discloses a sliding boom mounted atop a track type excavator. The sliding boom is used to delimb, to cut the top portion of full length trees, and to pile those trees awaiting further processing by a severing machine. Hahn discloses a machine having an articulated boom, a pair of sliding delimbing blades, a tree trunk severing saw, and a log sorting mechanism with two cradles to separate sawmill logs from pulpwood.
A variety of delimbing attachments have been developed to operate in combination with an articulated boom of a log loader. For example, U.S. Pat. No. 4,899,794 which issued on Feb. 13, 1990 to Hamby, Jr. and U.S. Pat. No. 5,406,997 which issued on Apr. 18, 1995 to Davison, disclose a tree delimbing device where the tree is drawn through a pair of limb stripping blades by the grapple of a log loader.
Another type of tree delimbing attachment for use in cooperation with an articulated loader boom is illustrated in U.S. Pat. No. 4,167,960 which issued on Sep. 18, 1979 to Wildey, and in U.S. Pat. No. 5,293,914 which issued on Mar. 15, 1994 to Hudson. In both the Wildey and Hudson devices, there is provided a pair of delimbing blades and a tree topping mechanism.
As discussed in U.S. Pat. No. 6,371,177 which issued to Larente on Apr. 16, 2002, the felling and harvesting of timber is not an easy task, especially for larger trees. The timber industry is continually in search of better and faster methods to harvest and process felled trees. One necessary task in the harvesting of trees is often the removal of pieces of the tree. For the timber industry, the most useful, and therefore most important part, of the tree is the healthy trunk with a mostly uniform diameter. Thus, other parts of the tree, such as its branches, are not as important and can be discarded. Another part of the tree than can be discarded is its top. Applicant has also been faced with the problem of having to remove one branch of a “Y” in a tree, which according to some current governmental regulations, must be trimmed within close tolerances of the remaining trunk of the tree.
Finally, as discussed in the prior art by Oilund in his U.S. Pat. No. 6,516,841 which issued on Feb. 11, 2003, for a tree felling and shaping apparatus, generally, a tree felling and shaping machine has a tree processor head which includes a central post, a cutting device at the bottom of the central post, and gripper and stripping means attached to the central post. The tree felling and shaping machine generally has a boom mounted to a vehicle and the tree processor head is typically mounted to the boom with a joint link system which as at least two degrees of freedom. The head can be tilted toward, or away from the machine about a first axis transverse to the boom. The head may also be tilted side to side about a second transverse axis, which is generally longitudinal to the boom when the head is upright, or may be pivoted about a second transverse axis which is at an angle from the first axis. These two degrees of freedom allow the head to be aligned with a tree that is not perfectly vertical. After the tree has been cut the head can be tilted about the first axis to move relative to the bottom of the machine to lay trees down transversely to the bottom for processing. During the processing period the tree processor head is in a generally horizontal position.
In other prior art of which applicant aware, in U.S. Pat. No. 3,074,446 which issued to Earl on Jan. 22, 1963, a machine for harvesting trees is disclosed in which a U-shaped jaw is placed around a standing tree and groups of grippers mounted on the jaw, taught to be four groups radially spaced apart around the tree, move into the jaw opening to clamp the tree, and when open leave the opening into the jaw unobstructed, the machine including a tree delimbing device and means including the grippers for moving the tree lengthwise of the jaw past the delimbing device while the grippers hold the tree.
Applicant is also further aware of U.S. Pat. No. 4,239,067 which issued Dec. 16, 1980 to Mononen for an apparatus for bulk-lopping, bucking and pre-stacking in forest harvesting, the apparatus including roll units fixed to a frame as well as roll units moveably mounted on the frame, the latter being moveable between a first open position for receiving tree trunks engaged by lifting and lopping arms and a second closed position defining an adjustable feeding pocket. Lopping blades on the arms lop limbs from the trunks as the trunks are fed through the feeding pocket under the action of the feed roll units. In particular, two longitudinally adjacent pairs of feed rollers are provided, each pair of feed rollers being in opposed relationship to each other upon the feed roll units being pivoted to their closed position.
Applicant is also aware of U.S. Pat. No. 5,148,843 which issued Sep. 22, 1992 to Cóté for a tree delimber with tree feeding means. The tree delimber of Cóté includes a telescoping boom, tree gripping means mounted on the front end of the boom and tree delimbing means and tree feed means mounted on the sleeve into which the boom telescopes. The tree feed means includes three feed rollers, one roller fixed on the sleeve and the other two rollers moveable toward each other and the one roller to hold a tree between all three rollers so as to feed the tree. The two rollers which are moveable towards each other are rotatably mounted on arms which in turn are pivotally mounted so as to engage the rollers with a tree held within a longitudinal passageway and up against the one roller rotatably mounted at the top of the passageway. The rollers thus may tightly grip a tree or, when the two arm mounted rollers are rotated from under the passageway, the tree within the passageway is released downwardly from being clamped within the rollers.